Scientific breakthrough in climate change study

A LITTLE-UNDERSTOOD molecule in the atmosphere could play an important role in reducing pollution and global warming, scientists believe.

Criegee biradicals were first hypothesised in the 1950s but have only now been isolated and measured.

New research shows they act as powerful “clean up” agents, neutralising atmospheric pollutants such as nitrogen dioxide and sulphur dioxide.

A byproduct of the process is the creation of aerosol droplets that “seed” planet-cooling clouds.

The molecules, known as chemical “intermediates”, should in theory have a significant influence on climate. However, until now they have never been directly observed. The new work involved watching simple Criegee intermediates react with various atmospheric molecules including nitric oxide, nitrogen dioxide and sulphur dioxide.

Scientists found the reaction rates were faster than expected, leading them to conclude that Criegee biradicals might have a bigger impact than previously thought.

The research is reported in the journal Science. Study leader Dr Carl Percival, from the University of Manchester, said: “We have been able to quantify how fast Criegee radicals react for the first time.

“Our results will have a significant impact on our understanding of the oxidising capacity of the atmosphere and have wide ranging implications for pollution and climate change.”